<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.bootcss.com/vue/2.4.2/vue.js"></script>
</head>
<body>
<div id="app">
    <p >Original message {{message}}</p>
    <p>Computed reversed message: "{{ reversedMessage }}"</p>
</div>
<script>
    var vm = new Vue({
        el : "#app",
        data : {
            message : "ni hao"
        },
        computed : {
            reversedMessage : function () {
                return this.message.split('').reverse().join('')
            }
        }
    })
</script>
</body>
</html>